Light field displays have emerged to provide viewers a more accurate visual reproduction of three-dimensional (“3D”) real-world scenes without the need for specialized viewing glasses. Such displays emulate a light field, which represents the amount of light traveling in every direction through every point in space. The goal is to enable multiple viewers to simultaneously experience a true 3D stereoscopic effect from multiple viewpoints, by capturing a light field passing through a physical surface and emitting the same light field using a display screen. Doing so has the potential to revolutionize many visual-based applications in areas as diverse as entertainment, business, medicine, and art, among others.
Examples of currently available light field displays include those based on holographic gratings, parallax barriers, or lenticular lenses. Holographic displays often require very large data rates and suffer from optical inefficiencies due to their use of interference to steer the light. They also produce blurred images when illuminated with different wavelengths, and as a result, have thus far been of limited use in commercial applications. Parallax- and lenticular-based displays rely on existing two-dimensional (“2D”) display technology and are therefore less costly to implement, but also suffer from poor image quality and a limited viewing angle.
Parallax barriers have narrow apertures that control the direction of light and also block most of the light from the pixels, which makes them very inefficient when a large number of views are used. Lenticular lenses steer the light by conventional refraction at an optical interface and require a relatively long focal length because of spherical aberration. This limits the viewing angel and also results in cross-talk (ghosting) from light from adjacent pixels entering the wrong lens.
A common theme among these displays is the difficulty to fabricate displays with light fields that are controlled with precision at the pixel level in order to achieve good image quality for a wide range of viewing angles.